Trimming device



1,626,232 April 26,1927 l A. A. GAGARIN TRIMMING DEVICE Filed Jan. 2. 1923 2 Sheets-Sheet 1 w anuentoz 1,626,232 April 26 1927 A A GAGARIN TRIMMING .DEVICE 2 Sheets-Sheet 2 Filed Jan. 2. 1925 Y @uve/Wto@ /n few /Z Gale afi?! 'i "iting the;v mvementof Patented Apr. A26, 1927.

UNITED STA-rss PATENT 'ori-len ANDREW A. GAGABIN, OF DETROIT, MICHIGAN, ASSIGNII. TO GEAR GBINDING MA- CHINE COMPANY, QF DETROIT, MICHIGAN, A CORPORATION 0F MICHIGAN.

` TRIMMING- DEVICE.

application mea January a, 1923. serial Nacional.

The invention lrelates to trimming me'chanism for grinding wheels and more particularly to a device which may be used for trimming a yrotary grinder' adapted for grinding spline shafts.`

,One method for grindin spline shafts consistsin trimming a grinder with a concave segment upon the periphery )of the. wheel correspondin exactly to a segment vof the finished work etween' the splines andA 1n also trimming the edges of the wheel to correspond with'the sides of the splines. lt is sometimes desirable to relieve the corners between the sides of the splines and the shaft itself and the usual practice forl accomplishing this result is to machine an undercut in the shaft before it is hardened. Une of the objects of my invention is to do away with the necessityjof machining the undercut in the work. Another object is to provide a grinding wheel with projecting corners for grinding the relief in the corners of the spline sha-ft. A further object is to obtain a simple trimmino mecha- 25 nisln whichwill trim a portion of the wheel to correspond exactly with ak segment of the finished work and will trim a second portion in such a manner as to form a grinding surface `for relieving the corners ofi the work.

vThese-.and lother objects are obtained by a simpieeonsftr'uetion which consists essenvtially" of two. diamond trimmers of diierent whichgaref rotatable about a common f ,oimter thegtrimmer ofl greater radius being edf-wit@ Suitable stops to limit its ,ovementtolfa predetermined segment.

`lgitudinal section of" 'my 'gfdevice ,showingits relael'ementsof a' grindingnniar-Figuregis a nd. levatioiiofthe''trin'fii'` 'g' mechanismshowin the --stops forflim` t `"e trimmers;

Figureffisfanend elevation at' the' Opposite end of the trimming mechanism showing the relation ofthe trimmer points to the grindingwheel;

Figure 4 is a crossjsection showing the grinder in engagement with awork piece;.

Figure 5 is across section' showingl the trimming mechanism in engagement wit the grinder wheel. v nvIn detail, A is a suitable base for the trimmer mechanism which is arranged to have'.

the axis of the arbor. 'lhe trimmer point l a relative longitudinal movement with respect to a rotating grinder wheel B. C represents a work holderfor supporting a work piece D, such as a spline shaft. The trimmer base A consists of twoupwardly extending a0 pedestals A and A2, the latter forming a. suitable bearing E for a rotatable arbor Ff which is preferably in longitudinal alignment with the axis of the work piece D.l y lThe arbor F may beof any suitable construction to form a rigid bearing but I as shown it is provided with a tapering surface E engaging the corresponding brushing E and the rear end of the arbor F2'has secured thereto a depending pin G. At the'for'ward end of the arbor F are the trimmer points H and I which are longitudinally spaced from each other and which are preferably provided with adjusting means J foravarying the distances of the respective points from is set to have a slightly greater radius than the trimmer point H. 1n the operation of the device the grinder wheel B is first moved relative to the trimmer so that its axis is in the plane of rotation of the trimmer point l-l. The arbor F ,may then-be rotated to trim a segment K in the periphery of the grinder wheel. During this operation the stop L, whichis pivoted upon a transverse. pin N in the trimmer pedestal A2, is in a downward position and the arbor F is free to rotate through va'complete cycle.

After completirlig the trimming movement of the trimmer` the arbor l* is rotated through a half revolution to bring the trimymer oint I in its upward position and the stop is also` placed in its upward position, Y thereby bringing its bifurcations L and L2 inalignment with the pin Gr. N and N. are

adjustable,l stops for the pin G and are set in aposition to `allow the rotation of the arbor F throuvh a predetermined angle.

When the stop has been set in its upward position, the grinder wheel ,B is moved relativev tofthe trimming mechanism to bring its axis inthe plane of rotation of the trim-` mer point I and the arbor F is then rotated` through the angle allowed bythe adjustable .stopsN andhlf. This movement trims the "segment in` the periphery of the grinder wheel to conform'exactly to thecontour of the Vspline shaft to'be ground.

For trimming, the edges of the grinder wheel, the" pedestal A contains the bifur- 11o cated bearing portions P which are arranged at opposite angles and contain the rotatable arbors Q having the transversely arranged arms R extending therefrom, on Which are mounted the trimming vpoints S. In the operation of the edge trimmer the Wheel B is moved into alignment With the trimmer points S Which are then given their trimming movement by means of the handles T which are attached to the arbors Q.

The grinding Wheel, Which has been trimmed With my improved trimming device, is shown in Figure 4 in engagement With a Work piece and it Will be seen that the projecting portions K on the grinder are used for grinding in the relief at the corners of the spline shaft therebywbviatingithe necessity of machining this relief before lia-rdening the shaft.

While I have shown thetrimmer points H and I as being located upon the same arbor and rotated about the same center, it is obvious that there are a number of modifications Which would come Within the scope of my invention and I do not Wishv to limit myself to the specific arrangement illustrated in the drawings. The essential part of the trimming mechanism consists in limiting the angular movement of the trimming point I to a predetermined arc and in so relating this angular movement With the sides of the grinder Wheel or With the edge trimmers that the grinder Wheel will be provided with projecting portions K for ,grinding the relief in the corners of the spline shaft.

l/Vhat I claim as my invention is :-y

1. In a trimming mechanism for grinder Wheels, a pluralityof ,trimming points for independently trimming ditferent'portions of the grinder Wheel to exactly conform to the contour of the Work, said points beingl rotatable about la common axis through arcs having diferent radii. l 2. In a trimming mechanism for grinder Wheels, a rotatable arbor, a trimmer point on said arbor for trimming a concave segmentl in the grinder Wheel, a second trimmer point upon said arbor for trimming a second' concave segment, said second trimmerf point having a greater radius than said lirst trimmer point, and means for limiting the rotative movement of said second trimmer point toa predetermined arc.

. 3. A trimming mechanism for grinder wheels, comprising means for trimming'a concave segment in the periphery'pof' the .grinding the cornersof the Work', and second trimming means of smaller radius than the .first and revoluble about the same center ,for

trimming a concavity in the perif'irry of said flanges.

4; The combination with a rotary grinder Wheel and a relatively reciprocable vWork holder, of a trimming mechanism comprising a member rotatable about the longitudnal axis of the Work,L a trimming point on said rotatable member for trimming a concave segment upon the periphery of said grinder wheel, and a second trimmer point on saidrotatable member for trimming a second concave segment of different radius in a different portion of said grinder wheel.

5'. The combination with a rotary. grinderwheel and a relatively reciprocable work holder, of a trimming mechanism comprising a member rotatable about the longitudinal axis of the work, a trimming lpoint on said rotatable member for trimming a concave segment upon the periphery of said grinder Wheel, a second trimmer point upon said rotatable member longitudinally spaced from 'said iirst trimmer point and having a greater radius, means for rotatingV said member, and an adjustable stop for limiting the angular movement of'said member to a Vpredetermined arc during the trimming of the grinder Wheel bysaid second trimming means.

.6. A trimming mechanism for grinder Wheels, comprising a supporting base relatively Yreciprocable with respect toa grinder Wheel, a. rotatable arbor journaled in said .base in alignment'vvith the plane ofA said grinder Wheel, a trimmer point on said arbor,

a second trimmer point of greater radius.

than said first trimmer' point, means for rotating said arbor, a member projecting from saidgarbor, an adjustable stop cooper'- ating With said member to limit the angular movement of said second trimmer pointtoV a predetermined arc,l and means for movingv f said stop out of operative relation with said.I member to permit unlimited rotation of saidl first trimmer point. 4 v

ANDREW A. GAGARIN.

In testimony whereof I affix my signature. 

